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CN-117564104-B - Method and device for measuring billet speed and head warpage

CN117564104BCN 117564104 BCN117564104 BCN 117564104BCN-117564104-B

Abstract

The invention discloses a method and a device for measuring billet speed and head warpage, the method comprises the steps of transmitting a symmetrical triangular linear frequency modulation continuous wave signal to a billet to be measured, wherein the symmetrical triangular linear frequency modulation continuous wave is used as a local oscillation signal and is generated by a detection device arranged at a preset position of an outlet of a rolling mill, generating an echo signal after the linear frequency modulation continuous wave is transmitted to the billet to be measured, mixing the local oscillation signal and the echo signal to obtain a difference frequency signal, carrying out spectrum analysis processing on the difference frequency signal to measure the target distance of the billet to be measured, calculating the difference value of the two target distances measured before and after the billet to be measured in the advancing direction of the billet to be measured, judging whether the difference value is in a first preset threshold range, and determining that the billet to be measured has no warpage if the difference value is in the first preset threshold range. According to the method, the linear frequency modulation continuous wave signal is adopted for measuring the distance and the speed, so that the method is not easily influenced by flowing water on the surface of the steel plate and water mist in a light path, has strong anti-interference capability, and improves the accuracy and the stability of steel plate warping measurement.

Inventors

  • LI XIANGDONG
  • MA XIAOJUN

Assignees

  • 北京光函数科技有限公司

Dates

Publication Date
20260505
Application Date
20220808

Claims (10)

  1. 1. A method for measuring billet speed and head warpage, comprising: transmitting a symmetrical triangular chirped continuous wave signal to a billet to be detected, wherein the symmetrical triangular chirped continuous wave signal is a chirped continuous wave which changes in time according to a triangle and has symmetrical slopes, and the symmetrical triangular chirped continuous wave is used as a local oscillation signal and is generated by a detection device arranged at a preset position of an outlet of a rolling mill; generating an echo signal after the linear frequency modulation continuous wave is shot to the steel billet to be detected, and mixing the local oscillation signal and the echo signal to obtain a difference frequency signal; Performing spectrum analysis processing on the difference frequency signal to measure the target distance and the advancing speed of the steel billet to be measured; Calculating the difference value of the two target distances measured front and back in the travelling direction of the steel billet to be measured, judging whether the difference value is in a first preset threshold range, and if the difference value is in the first preset threshold range, determining that the steel billet to be measured has no warpage.
  2. 2. The method of measuring billet velocity and head warpage according to claim 1, further comprising: if the difference value is not in the first preset threshold range, determining whether the steel billet to be detected is warped or buckled according to the positive and negative of the difference value.
  3. 3. The method of claim 2, further comprising determining whether the target distance is less than a first predetermined distance, and if the target distance is less than the first predetermined distance, determining that the steel billet to be tested is warped.
  4. 4. The method of claim 3, further comprising determining whether the target distance is greater than a second predetermined distance, and if the target distance is less than the second predetermined distance, determining that the steel billet to be tested is buckled.
  5. 5. The method of measuring billet velocity and head warpage according to claim 4, wherein the target distance and the travelling velocity are obtained by: Calculating a signal S S transmitted to the steel billet to be tested according to the formula (1): (1); wherein A is the amplitude of electromagnetic wave, f 0 is the center frequency, K is the slope, Is the initial phase; And (3) calculating an echo signal obtained by reflecting the signal S S after the signal S S is emitted to the steel billet to be detected according to the formula (2): (2); Wherein, the In order for the transmission delay to be a function of, =2(R 0 -υ 0 t)/c; Mixing the echo signal S r with the transmitting signal S S , and calculating the phase corresponding to the difference frequency between the echo signal S r and the transmitting signal S S according to the formula (3) after low-pass output: (3); According to the formula (4) And (3) performing transformation: (4); Wherein, the For the time delay of electromagnetic wave to the echo of the original static object, the motion of the billet is considered, and the echo time delay is overlapped ; Bringing equation (4) into equation (3), and Conversion to the following formula (5): = - + (5); Wherein, f b is the frequency of the difference frequency signal, K b is the slope of the difference frequency signal; Is the primary phase of the difference frequency signal; = ; = ; ; = , Is the echo center frequency; f d is Doppler shift due to billet motion; and respectively constructing two equations f b Upper part and f b Lower part(s) through the upper slope and the lower slope of the symmetrical triangular linear frequency modulation continuous wave signal, and solving the target distance and the travelling speed of the billet to be detected.
  6. 6. The method according to claim 5, wherein after mixing the local oscillation signal and the echo signal to obtain a difference frequency signal, before the spectrum analysis processing is performed on the difference frequency signal, further comprising: and filtering, amplifying and AD sampling the difference frequency signal obtained by mixing.
  7. 7. A billet speed and head warp measuring device, comprising: The system comprises a local oscillation signal transmitting module, a rolling mill outlet and a rolling mill outlet, wherein the local oscillation signal transmitting module is configured to transmit a symmetrical triangular chirp continuous wave signal to a billet to be measured, the symmetrical triangular chirp continuous wave signal is a chirp continuous wave which changes according to a triangle in time and has symmetrical slopes, and the symmetrical triangular chirp continuous wave is used as the local oscillation signal and is generated by a detecting device arranged at a preset position of the rolling mill outlet; the difference frequency signal determining module is configured to generate an echo signal after the linear frequency modulation continuous wave is emitted to the steel billet to be detected, and the local oscillation signal and the echo signal are mixed to obtain a difference frequency signal; the distance measurement and speed measurement module is configured to perform spectrum analysis processing on the difference frequency signal so as to measure the target distance and the travelling speed of the steel billet to be measured; The first warping determination module is configured to calculate a difference value of the two target distances measured front and back in the travelling direction of the steel billet to be detected, judge whether the difference value is in a first preset threshold range, and determine that the steel billet to be detected has no warping if the difference value is in the first preset threshold range.
  8. 8. The apparatus for measuring billet velocity and head warpage according to claim 7, further comprising: and the second warping determining module is configured to determine whether the steel billet to be detected is warped or buckled according to the positive and negative of the difference value if the difference value is not in the first preset threshold range.
  9. 9. The apparatus for measuring billet velocity and head warpage according to claim 8, further comprising a third warpage determining module; The third warping determination module is configured to determine whether the target distance is smaller than a first preset distance, and if the target distance is smaller than the first preset distance, determine that the steel billet to be tested is warped.
  10. 10. The apparatus for measuring billet velocity and head warpage according to claim 9, further comprising a fourth warpage determining module; The fourth warping determination module is configured to determine whether the target distance is greater than a second preset distance, and if the target distance is smaller than the second preset distance, determine that the steel billet to be detected is buckled.

Description

Method and device for measuring billet speed and head warpage Technical Field The invention relates to the technical field of steel smelting, in particular to a method and a device for measuring billet speed and head warpage. Background In the steel rolling process, the steel billet head is easy to collide with equipment or a detection instrument due to the upward bending of the steel billet head, the steel strip cannot smoothly enter a rolling mill to cause a steel stacking event, and the steel billet buckling head (the downward bending of the steel billet head) is easy to cause the steel billet to collide with a frame roller or a roller way to cause the plate blank to drill into the lower part of the roller way, so that a plurality of disadvantages are brought to production. The accuracy of billet speed measurement directly relates to the accurate operation of the flying shear system, and inaccurate data can lead to material waste, thereby increasing production cost. Therefore, the speed of the steel billet and the warping degree of the head are accurately monitored in real time, and data are timely and accurately transmitted to a control system, so that the method has great significance in steel rolling control. In the steel rolling process, a large amount of oxide generated by spraying and cooling a roller way of a rolling mill and cleaning the surface of rolled steel is also needed, a small amount of flowing water is easy to remain on the surface of a middle blank, a large amount of water mist is formed around the middle blank, the steel rolling environment is poor, and various interferences are more. At present, two main measuring modes are available for the speed and the warping degree of the steel billet, one is laser measurement, and the other is speed measuring of a speed measuring roller. The laser measurement precision is higher, but is extremely easy to be influenced by flowing water on the surface of the steel plate and water mist in an optical path, so that problems are easy to occur in the application site with severe hot rolling, and the reliability is lower. The speed measuring roller is not easily affected by mist and flowing water on the surface of the steel plate, but the speed measuring precision is easily affected by slipping and abrasion. In summary, the above-mentioned measuring methods for the billet speed and the degree of warpage have certain limitations, and it is difficult to obtain a good measuring effect, and an improvement is necessary. Disclosure of Invention The invention provides a method and a device for measuring billet speed and head warpage, which are used for overcoming at least one problem in the prior art. According to a first aspect of embodiments of the present disclosure, there is provided a method for measuring billet speed and head warpage, including: transmitting a symmetrical triangular chirped continuous wave signal to a billet to be detected, wherein the symmetrical triangular chirped continuous wave signal is a chirped continuous wave which changes in time according to a triangle and has symmetrical slopes, and the symmetrical triangular chirped continuous wave is used as a local oscillation signal and is generated by a detection device arranged at a preset position of an outlet of a rolling mill; generating an echo signal after the linear frequency modulation continuous wave is shot to the steel billet to be detected, and mixing the local oscillation signal and the echo signal to obtain a difference frequency signal; Performing spectrum analysis processing on the difference frequency signal to measure the target distance and the advancing speed of the steel billet to be measured; Calculating the difference value of the two target distances measured front and back in the travelling direction of the steel billet to be measured, judging whether the difference value is in a first preset threshold range, and if the difference value is in the first preset threshold range, determining that the steel billet to be measured has no warpage. Optionally, the method for measuring the billet speed and the head warpage further comprises: if the difference value is not in the first preset threshold range, determining whether the steel billet to be detected is warped or buckled according to the positive and negative of the difference value. Optionally, the method for measuring the billet speed and the head warpage further comprises: Judging whether the target distance is smaller than a first preset distance or not, and if the target distance is smaller than the first preset distance, determining that the steel billet to be tested is warped. Optionally, the method for measuring the billet speed and the head warpage further comprises: judging whether the target distance is larger than a second preset distance, and if the target distance is smaller than the second preset distance, determining that the steel billet to be detected is buckled. Optionally, the target distance an